The Boy Surface at Oberwolfach

The Boy surface is named after Werner Boy, who constructed this surface, which is an immersion of the real projective plane in Euclidean 3-space, in 1901 in his thesis. The doctoral adviser was David Hilbert. The model of the Boy surface in front of the Institute's library building has 3-fold rotational symmetry and minimizes the Willmore functional which measures elastic energy.